1. Field of the Invention
The present invention relates to measuring device and more particularly pertains to a measuring template for measuring outside and inside diameters, especially of objects with predetermined diameters like pulleys, cylinders and the like.
2. Prior Art
Prior to the present invention there have been numerous devices in a variety of configuration that fulfill the objective of measuring inside and outside diameters accurately. There are all forms of calipers, micrometers, rulers, tapes, straight edge scales and gauges made for this purpose. One characteristic of these prior art devices that is substantially different from this present invention is that the prior art devices have to straddle the entire diameter of the object that they measure. The prior art devices are used for specific measuring application and therefore have limited applications. For example, when a pulley is installed on machinery the diameter would be difficult to measure with accuracy using traditional devices like rulers, straight edge scales and tapes. Tapes, rulers and straight edge instrument are not accurate in measuring the diameter of an object if the diameter points are not shown. In addition, protrusion of a shaft through the center of the pulley on which the pulley is installed would obstruct traversing the pulley diameter for measurement.
Using calipers and micrometer would give accurate result but have limitations. The two fingers of the calipers would have to be longer than the radius of the pulleys to perform the measurement. To hold a caliper over the pulley to measure the diameter, there would have to be enough caliper depth to fit over the shaft and in addition the diameter would have to be marked on the pulley. The use of micrometer in this application would also be limited like the calipers. In addition the micrometer would require so much space for operation than is available within the confinement of a pulley compartment. Another disadvantage of these measuring devices is their physical size and cost as the size of the object to be measured becomes large.